Wire respooler



'March24, 11970 w.G-.PE sTA|. ozz| 3, 2,

. WIRE RESPOOLER Filed Jan. 27, 1967 4 Sheets-Sheet 1 BY I Z arrow/5y March-24, 1970 w Pgsnmzzr 3,502,828 v WIRE RESPOOLER Filed Jan. 27, 1967 4Sheets-Sheet 2 w. a. PESTALOZZI 3,502,828

March 24, 1970 WIRE RESPOOLER 4 Sheets-Sheet 3 Filed Jan. 2'7, 196'? INVENT OR.

MAL/,9 a. P525594 022/ 7 'flr R/VE) 0- sw p; y

' March 24, 1970 w. GQPESTALOZIZI 3,502,

I WIRE RESPOOLER Filed Jan. 27, 1967 I 4Sheets-Sheet 4 INVENTOR. A/ALL/fi/V 6'. 1 5.5 7/9LOZZ/ BY 2 a i 197 7 ORA E Y United States Patent 3,502,828 WIRE RESPOOLER William G. Pestalozzi, Carlisle, Mass., assignor, by mesne assignments, to Camden Wire Company, Inc., Camden, N.Y., a corporation of New York Filed Jan. 27, 1967, Ser. No. 612,135 Int. Cl. B65h 25/14 US. Cl. 20061.18 4 Claims ABSTRACT OF THE DISCLOSURE An automatic wire respooler to take twisted stranded copper wire from a pay off spool and wind it onto a take up spool. The respooler has a detecting finger which signals broken projecting strands to cause the respooler to stop so that an operator can twist in the projecting strand. A small fast response dancer arm assembly together with a motor connected to the pay off reel serve to maintain wire tension constant. The motor is connected to run as a generator when the pay off spool is rotated by the pull of the take up spool. Motor field strength is varied as a function of dancer arm position so that the amount of tension provided by the motor in combination with the wire slack take up provided by the dancer arm operate together to maintain wire tension constant. Other features include a sizing die that automatically snaps open as soon as a broken strand is detected.

This invention relates in general to a wire respooler and more particularly to the apparatus which is employed for placing multi-strand twisted copper wire onto spools for shipment including those features of the apparatus which maintain constant wire tension, detect and signal projecting broken strands and brake the operation when required as when faults are detected.

Wire respoolers are known which involve the pulling of wire off one reel onto the final reel on which the wire is shipped. This respooling operation is accomplished primarily to permit inspection of the wire for flaws and in particular to permit the detection and correction of projecting broken strands. The respooling operation is also employed to'size the diameter of the wire by passing the twisted multi-strand wire through a sizing die.

The most commonly used technique of detecting projecting strands has been for the operator to lightly hold the wire as it passes from one spool to the other. As the wire runs across his hand, the operator through his sense of touch determines when a projecting broken strand exists. When he feels a projecting strand he shuts down the equipment manually, takes the broken projecting strand and twists it back into the wire so that it no longer projects. This operation requires continuous attendance by an operator and because it relies upon a subjective response to flaws it does not always have the minimum error rate.

Accordingly, it is an important purpose of this invention to provide a technique in a wire respooler for automatically detecting projecting strands so that operator visual or tactile response need not be employed.

In connection with this projecting strand detection it should be pointed out that the problem is not so much the existence of occasional breaks in the strand as in the fact that the broken strands may project from the wire. If broken strands project from the wire then when the wire is later insulated for conversion to ordinary electric cables, the projecting strands will be close to the surface of the insulation if indeed they do not extend through the insulation. In any case, this generates an electric shock hazard.

Furthermore, in the process of placing insulation onto stranded copper wire the stranded copper wire is pulled 3,502,828 Patented Mar. 24, 1970 through a necked down area which sizes the insulation. If a projecting strand catches in the necked down area it may bunch up as the wire continues to be pulled through the necked down area. This is called bird-caging and requires that the insulation operation stop.

It is further important in respooling the stranded wire that substantially constant tension be maintained in the wire. This is particularly true where the relatively soft and ductile copper wire is involved. There are, of course, many techniques for maintaining tension within certain limits. Many of these techniques are very cumbersome and require large equipment.

Accordingly, it is a further purpose of this invention to provide a somewhat simplified and less cumbersome tension control device in a respooler.

Whenever a broken strand is detected, it is important that the respooler be stopped as soon as possible so that the broken strand can be twisted back into the main body of the wire.

Thus, it is a further purpose of this invention to provide a sensitive and responsive braking mechanism to bring the respooler to a halt automatically whenever a projecting strand fault is detected and to do so in such a fashion as to maintain the tension on the wire as constant as possible to prevent breaking or spilling of the wire.

Other objects and purposes of this invention will become apparent from the following detailed description and figures in which:

FIG. 1 is an elevation view of one embodiment of the wire respooler of this invention;

FIG. 2 is a plan view of the FIG. 1 respooler;

FIG. 3 is an end view of the FIG. 1 respooler as seen from the left hand side of FIG. 1;

FIG. 4 is a simplified plan view of the portion of the respooler wherein the projecting strand detector fingers are located;

FIG. 5 is an elevation view of the same portion of the respooler that is shown in FIG. 4;

FIG. 6 is a perspective view of the projecting strand detection fingers showing a multi-strand twisted wire being reeled through the fingers;

FIG: 7 is a cross-sectional view of one of the fingers of FIG. 6 taken along the plane of travel of the wire;

FIG. 8 is a perspective view of a portion of the wire tension take up mechanism;

FIG. 9 is a side view of a wire break detecting mecha nism;

FIG. 10 is a perspective view of the sizing die and associated die mechanism;

FIG. 11 is a simplified top view of a portion of the FIG. 10 mechanism to show the operation of the FIG. 10 mechanism;

FIG. 12 is an electrical schematic of certain of the circuitry required in connection with the projecting strand detecting braking operation involved in the FIG. 1 respooler.

The respooler generally A broad understanding of the operation of the respooler with particular reference to FIG. 1, 2 and 3 is useful and perhaps necessary in order to understand the significance of the operation of the detailed features such as the detector fingers and the mechanisms by which tension on the wire is kept constant.

With particular reference to FIG. 1, it may be seen that wire 20 is being spooled from a clockwise rotating pay off reel 22 to a counter-clockwise rotating take up spool 24. Thus the wire shown at the top of FIG. 1 is traveling from left to right.

Motive power for the respooling is provided by a drive motor 26 which through a series of belts 28, 29 pulleys 3 30, 31 and gears 32, 33 drive the take up spool 24 in the counter-clockwise direction shown by the arrow. This take up mechanism as well as the rest of the take up mechanism that is to be described herein is shown generally on the right side of FIG. 1 and is supported on take up stand 35.

Because of the considerable mass and velocity (about 2,000 feet per minute cable velocity) involved it becomes necessary from the point of view of maintaining control, to operate under tension by applying a continual braking force on the pay off reel 22 during operation. The braking force employed is a counter-clockwise torque applied to the pay off reel 22 through the motor 40. A belt 42 couples the motor to the clockwise rotating pay off reel 22. This pay off portion of the respooler is shown generally on the left hand side of FIG. 1 and is supported on a pay off stand 44.

Between the pay off stand 44 and the take up stand 35 there is positioned a detector stand 46 which includes a dancer arm assembly 48 for the purpose of taking up or adding slack in the wire 20 in such fashion as to aid in maintaining wire tension constant during operation. The detector stand 46 also contains a pair of detector fingers '50, 51 which are identical in structure except for the fact that one of the fingers 50 faces downward and the other finger 51 faces upwardly. Between these two fingers 50 and 51 the broken strands that project in any direction are detected.

The wire 20 itself is guided from pay off reel 22 to take up reel 24 through and by a series of roller guides 53, 54 and 55 as well as a series of guide pulleys 56, 57, 58 and 59. These roller guides and guide pulleys operate in the known and usual fashion to perform the known and usual results. However, there is one guide pulley 62 which is part of the dancer arm assembly 48.

It might be noted at this point that the dancer arm assembly (see FIG. 1) includes dancer arm 64 which is pivoted at one end to the top of the detector stand 46, and a spring 66 under tension connected between the lower portion of the arm 64 and the detector stand 46 so as to tend to pull the arm 64 in a counter-clockwise direction around the pivot point 68. The spring 66 will contract or expand in such a fashion in response to changes in the tension of the wire 20 so as to tend to compensate for such changes in wire 20 tension. There is more than this involved in the dancer arm assembly operation as will be discussed in greater detail further on. However it can immediately be seen that as the tension in the wire decreases the force on the pulley 22 tending to pull it to the left will decrease so that the spring 66 will pull the arm 64 and thus the pulley 62 to the right. This will increase the length of wire travel sli htly thereby tending to increase the tension on the wire and tending to compensate for the decrease in tension. As the tension in the wire increases, the wire will tend to straighten out between the pulleys 56 and 57 thereby pulling the pulley 62 to the left against spring 66 tension. This Will decrease the length of travel of the wire 20 and thus tend to decrease tension on the wire 20. The two extreme positions of the guide pulley 62 are shown in FIG. 1. The low tension end position is shown in solid lines and a position A close to the extreme high tension position is shown in dash dot lines.

One other significant feature which may be noted in this over all view of the respooler is a sizing die assembly 70 located in the path of the wire 20 between the guide pulley 59 and the take up spool 24. The sizing die assembly 70 is described in greater detail in connection with FIGURES 10 and 11.

Detector fingers The detector fingers 50 and 51 are of major importance in making this respooler automatic. It is because of these detector fingers 50 and 51 that it is possible to do away with the older technique of manually feeling the wire as it is respooled to detect projecting strands. Because of these mechanical detecting fingers 50 and 51, an automatic wire respooler becomes possible.

FIGURES 4, 5, 6 and 7, all located on a single sheet of the drawings, illustrate the structure and operation of the detector fingers 50 and 51. The two detector fingers 50 and 51 are identical in structure except that the detector finger 50 is downwardly facing and the detector finger 51 is upwardly facing so that between them they catch all of the projecting strands frorii the wire 20.

Both detector fingers 50 and 51 are supported on the detector stand 46 by a steel leaf spring support 72. An aluminum block 74 and a slotted ceramic insert 76 constitute the rest of the detector finger 50. Experience has shown that the distance between the first detector finger 50 and-the guide pulley 57 should be at least eight inches in order to allow loose strands to fly free from the wire surface after having been smoothed while traveling over the guide pulley 57.

The detector finger 50 functions in such a fashion that if a loose strand 20s is projecting upwardly or sidewardly from the wire 20 as the wire travels to the right in FIG. 6 the loose strands 20s will hit the aluminum block 74 thereby establishing the electrical path to ground and creating a signal indicating this particular type of fault. The signal is then employed, by fairly standard electrical means (see FIG. 12) to trigger appropriate relays and solenoids so as to bring this entire respooler to a stop. Once the respooler has been brought to a stop it is reversed by the operator and run back until the projecting strand is presented to him. The operator can then twist the projecting strand 20s into the wire 20 and the respooling operation can proceed.

The ceramic insert 76 is required in order to insulate the wire 20 from the aluminum block 74. The ceramic insert 76 is bonded to the aluminum block 74 with epoxy cement and positioned so that the leading edge of the ceramic insert 76 protrudes forward slightly (a few thousands of an inch) from the aluminum block. The protrusion of the insert 76 reduces the electrical bridging effect between the wire 20 and the aluminum block 74 caused by copper powder build up. Because of this protruding feature of the ceramic insert 76 it has been found that the finger 50 needs recleaning only relatively infrequently. The ceramic insert 76 employed in one embodiment was provided with a channel (in which the wire 20 travels) that was 0.010 inch wider than the nominal wire diameter and approximately one and one-half wire diameters deep. With such dimensions it was possible to catch substantially all projecting strands regardless of the direction in which they project by using only two oppositely facing fingers 50 and 51. The wall thickness of the ceramic insert 76 is held to the minimum dictated by structural and mechanicalstrength consideration. A wall thickness of approximately 0.030 inch was achieved by use of a ceramic material, known by the trade name of Henium, sold .by the Henium Corporation of America. However, any hard ceramic material can be used, since its main function is to provide insulation, as long as the dimensions of the ceramic material are made compatible with its strength characteristics. Obviously, it is desirable to keep the ceramic insert 76 with as small a wall thickness as possible so that even relatively minor projecting broken strands will be detected. The smaller the wall thickness of the ceramic insert, the higher will be the quality of the resulting wire.

The steel leaf spring support 72 is provided so that the detecting finger 50 may pivot away from the running wire 20 where snags or other major obstructions develop in the wire and thus avoid damage to the finger 50 as well as prevent catching projections on the finger 50 with the resultant bird-caging.

FIGURE 12 illustrates the electrical circuitry associated with the finger 50 that provides fast response to the detection of a projecting-strand. The running wire 20 is held at ground potential by any convenient means such as grounding any one of the rollers or pulleys over which it runs. When a broken strand 20s bridges over to the aluminum block 74 the aluminum block is thereby grounded. The aluminum block is mounted on a steel leaf spring 72 which in turn is mounted onto a Bakelite insulating block 78, which block 78 in turn is mounted onto the detector stand 46. In this fashion, the aluminum block 74 and leaf spring 72 are normally insulated from ground.

A projecting strand fault will provide an electrical contact from the grounded wire 20 to the aluminum block 74 over only a very short period of time. Where the wire 20 travels at 2,000 feet per minute and a projection of about M; of an inch is being sensed, a pulse having a duration of approximately of a second (or 300 micro-seconds) will be generated. No presently known relay will respond to a pulse of that duration. The fastest commercially available electro-mechanical relay requires a pulse duration of one milli-second or more in order to obtain a change in state of the relay.

FIGURE 12 is a standard, well known type of circuit that has been successfully used in connection with this invention. In connection with this FIG. 12 circuit it might also be well to initially point out that the impedance threshold for triggering has been set relatively low. The circuit of FIGURE 12 is made so that it will not respond unless the resistance drops to below 3,000 ohms for a period of time of a few micro-seconds. This low three thousand ohm threshold reduces the sensitivity to copper powder build up or other conducting contaminants on the insulating ceramic inserts 7-6. In spite of the fact that the ceramic insert 76 does project forwardly, it is periodically necessary to clean the copper powder off the finger 50. The operator is made aware of whenever the powder build up becomes too great because he will get a false indication of projecting wire faults.

Because FIG. 12 is a known type of circuit, there is no need to describe its operation in detail. Suffice it to say that the terminal T is connected to the aluminum block 74 of the finger 50 so that when a projecting strand contacts the aluminum block 74, a circuit to ground from the terminal T is completed. As a consequence the normally biased off silicon control rectifier 2N877 is turned on to turn on the relay R and consequently the relay R all of which results in turning power off to the motor 26 and braking the payoff reel 22 and take up spool 24.

The detector finger 50 design in combination with the FIG. 12 electrical response circuitry is particularly adapted for use with fine stranded wire. For example, it has been successfully employed with twisted stranded wire consisting of 41 strands of number 34 wire; number 34 wire having a diameter of 0.051 inch. When one of these number 34 strands is projecting from the twisted wire in a respooling operation where the twisted wire is being pulled along at 2,000 feet per minute it can be seen that there is a need for a very sensitive response to the projecting broken strands. It is similarly important that the response be instantaneous as well as sensitive. The need for this instantaneous response is required to latch onto a signal which may have a duration as low as 300 microseconds.

It is further important that projecting broken strands or birdcaged strands not catch on the detecting finger 50. If these strands were to be caught on the finger 50, then there would be further birdcaging and ultimately a wire break. The detecting finger 50 is designed to avoid this result .by having the channel, within which the wire 20 rides, open and by mounting the finger 50 in a resilient manner. When large projecting strands or birdcaged wires come along, the detecting finger 50 will flex and permit the fault to ride through without catching on finger 50. Because the finger 50 is thus open, it is important that at least two sensing fingers 50 and 51 be employed in order to detect projecting broken strands no matter in which direction they project.

Another important feature of this design is the fact that the detector Zone is sufficiently opened and spaced from guide rollers and guide pulleys so that there is something of a whipping action to the wire 20 between the last pulley off of which it comes (i.e., pulley 57) and the first detecting finger 50 so that broken strands can be whipped out. It is important that the design of the respooler be such that the broken strands that are smoothed down or partially buried by guide pulley or roller action be allowed to free themselves from the surface of the wire prior to reaching the first detector finger 50. It is desirable to detect and twist in all broken strands, those that are partially buried as well as those that are on the surface, since the partially buried ones might be whipped out by later working of the wire unless they are detected and corrected at this stage.

One other feature should also be noted at this point which is that the design of the respooler is such that there is no need to thread the wire 20 through an aperture when setting up the respooler. Even the sizing die 94 is popped open (as is explained further on) so that the wire can be laid into the sizing die when setting up the respooler. Furthermore, the finger 50 design is such that the wire is laid into a channel on the insert 76 rather than threaded through an orifice.

A few additional notes concerning the finger 50 and 51 might be kept in mind in adapting this respooler to use with different Wires and for different sensitivity re quirements.

The fingers 50 and 51 are easily dismountable so that they can be replaced with fingers having different size ceramic inserts 76 (that is, different size channels) so as to accommodate different wire sizes. Furthermore, the thickness of the insert 76 can be varied in order to achieve various sensitivities. By sensitivity here is meant the minimum amount of projection that will be detected by the finger 50.

A technique of increasing sensitivity is to add detecting fingers. Each detecting finger 50 works the wire to some extent and causes additional broken strands to work free and project. Thus four fingers 50 instead of two fingers will provide maximum sensitivity. It is not likely that additional fingers beyond four will increase sensitivity to any significant extent. Indeed, it is unlikely that four fingers will be required for practical purposes.

Wire tension maintaining mechanism The motor 40, employed in the embodiment shown at the pay off stand 44, is of the type described in United States Patent No. 3,221,237 issued on Nov. 30, 1965 to Mr. Aram Kalenian. The power line is connected to the motor 40 in such a fashion that the motor 40 would, absent the rest of the dynamics of this respooler, drive the pay off reel 22 in a counterclockwise direction. However, with the take up spool 24 drive 26, the wire 20 is purposely pulled off the pay off reel 22 in a manner such as to force the pay off reel 22 to rotate in a clockwise direction. As a consequence, the motor 40 is being driven as a generator and the effect of the motor 40 is to provide a counter-clockwise torque which maintains tension on the wire 20.

In the embodiment illustrated, the motor 40 had field connections such that the making or braking of the limit switch 80 (see FIG. 8) selects one of two field strengths so as to establish one of two predetermined torque conditions. As a consequence, during running it is possible for either a lower torque condition or a higher torque condition to be established in the motor 40, which in turn means that one of two tension base points may be established or selected for the wire 20. Because of the dancer arm 24 operation, actual tension on the wire 20 will range around these two torque determined tension conditions. In this fashion, a range of conditions that affect wire 20 tension are created and are so employed as to maintain the wire tension relatively constant.

In operation what occurs is that every so often slight irregularities occur in the wire 20 on the pay off reel 22 causing a change in tension that result in a dancer arm 64 movement. In response to the change of wire tens-ion usually where wire 20 tension increases, the dancer arm 64 moves outward to contact the limit switch 80 so as to change the counter-clockwise torque imposed by the motor 40. More explicitly, the irregularity which causes this change of tension can be due to the fact that the wire on the pay off reel may be wound on the pay oif reel in an irregular fashion so that certain turns of wire will be buried in the reel and require an additional force to pull the wire free from the rest of the turns. The consequent increase in tension usually occurs for a short period of time. The tension maintaining technique of this invention is one that reacts quickly enough to this change of tension so as to provide a compensation that maintains tension within allowable limits for the period of time during which the irregularity persists. To continue with the example, if the change in tension is due to a turn of wire in the pay olf reel 22 being buried under other turns of wire, then the tension in the wire 20 will tend to considerably increase as the buried turn is pulled free. As a consequence, the dancer arm 64 will give up slack and will be pulled up and to the left (as seen in FIG. 1). This will cause a roller arm on the limit switch 80 to be actuated by contact with the dancer arm v64 (see FIG. 8). The limit switch 80 simply switches the field strength of the motor 40 to one whereby a lower counter-clockwise torque is established. As a consequence the increasing tension on the wire 20 is relieved so that tension is maintained relatively constant. When the irregularity which is the cause of the increasing tension passes, the tension on the wire 20 tends to decrease thereby permitting the spring 66 to pull the dancer arm 64 back to a position that tends to take up the slack thus created in the wire 20 and at the same time to release the limit switch 80. This restores the previous torque condition and maintains wire 20 tension.

It should be appreciated that the dancer arm assembly 48 operation is such that the dancer arm both responds to changes in wire 20 tens-ion and, because it takes up or gives up slack, also aids in controlling and evening out wire tension.

A gradual longer term change in the tension of the wire 20 arises from the fact that the diameter of the wire spool at the pay off end gradually decreases as the respooling operation goes on. This results in an increase in tension that will cause the dancer arm 64 to gradually creep up toward the limit switch 80 as its normal operating position. Thus at the end of the respooling operation, the dancer arm 64 will generally be in contact with the limit switch 80 more frequently. Accordingly, the normal motor 40 condition at the end of the respooling operation will approach very nearly the low torque condition of the motor 40. The limit switch 80 is positioned so that the dancer arm 64 will contact the limit switch at about the mid position of the, maximum possible dancer arm 64 excursion. This means that even at the end of the respooling operation where the motor 40 may be in the lower torque condition, there is still room for operation of the dancer arm 64 'to moderate any temporary increases in tension that may occur at this terminal portion of the respooling operation. The dancer arm 64 is still able to swing further up and out thereby give up slack to smooth increases in wire 20 tension.

In one embodiment where the wire 20 being respooled was composed of 41 strands of number 34 wire, it was found that an average tension of approximately 18 pounds was optimum. On an empirical basis, to provide smooth operation it was found that the point at which thedancer arm was set to contact the limit switch 80 was at approximately 16 pounds of tension. As a general rule, the limit switch may have to be moved slightly in position to obtain smooth operation. This will depend upon the particular wire being respooled and the dimensions of the respooler involved.

Braking There are two conditions under which it is important that the respooler be brought to a stop. One condition is the relatively infrequent condition where there is a complete break in the wire being respooled. Then it is important that the respooler be braked so as to avoid the danger to men and equipment of having a loose end flapping around at high speed. The more difficult and more critical braking operation is brought into play when a projecting broken strand is detected. It is then important that the respooling operation be decelerated to a stop as quickly as possible while maintaining tension so that the wire will not rupture. One of the significant advantages of the combination of the dancer arm assembly 48 and limit switch 80 control over motor 40 torque is that this combination can also be employed during braking after flaw detection to maintain substantially constant tension on the wire 20 during the deceleration period.

At the take up stand 35, as a consequence of the closing of the relays R and R when the finger 50 detects a fault, the take up spool 24 is braked by removing power from the drive motor 26, applying dynamic braking, as well as by employing a standard magnetic particle brake. Both methods are employed in the usual well-known fashion. Accordingly, the braking and deceleration at the take up stand 35 is all of a standard and known sort.

At the pay off stand 44, the dancer arm assembly 48 and limit switch 80 operate in the same fashion as they do under normal running operation to maintain constant tension. In addition, the actuation of the limit switch 80 serves to remove or apply the brake to the pay off reel shaft. Specifically, this brake is applied to the pay off reel 22 shaft when the limit switch is not actuated and is removed by actuation of the limit switch 80.

What occurs is that both the pay off reel 22 and the take up spool 24 are being simultaneously braked or decelerated. However, absent very complex synchronizing equipment it is not possible for these two substantially separate devices to be decelerated at the same rate. Accordingly, it must be expected that there will be changes in the tension of the wire 20. But because of the dancer arm assembly 48 in combination with the two other and higher levels of counter-clockwise torque available (depending upon whether the limit switch 80 is closed or opened) it becomes possible to compensate for the fact that the deceleration of the pay off reel 22 and take up spool 24 will not match exactly over the entire deceleration period.

It should be appreciated that during this braking operation the levels of counterclockwise torque required from the motor 40 are greater than that required during normal operation. Thus, although the limit switch 80 operates in exactly the same fashion during the braking operation as 'it does during the normal running operation, the values of the voltage which the limit switch 80 causes to be applied to the field of the motor 40 will differ during these two modes of operation. During normal running operation, the state of the limit switch 80 will determine whether a low run tension or a high run tension counter-clockwise torque will be applied. The low run tension will occur during running when the limit switch 80 is actuated and will result from applying a relatively low voltage to the field of the motor 40. When the limit switch .80 is not actuated during running, a somewhat higher voltage is applied to the field of the motor 40 to provide high run tension. However, during the braking operation the magnitude of the voltage applied to the field of the motor 40 even when the switch 80 is actuated will be higher than either of these two running condition voltages. When the switch 80 is not actuated during this braking phase of operation, the pay off brake remains energized and, in addition, a high voltage is applied to the field of the motor 40 to provide a high stall tension on the wire 20'. Then when the switch 80 is actuated, the pay off brake is released and, in addition, a somewhat lower voltage is applied to the field of the motor 40 to provide a low stall tension (which is greater than the high run tension) on the wire 20.

FIG. 9 illustrates a feature of this invention which is required in case a complete break in the wire 20 occurs and when the pay off reel 22 is emptied. With reference to FIGS. 9 and 1, a shaft 84 is connected by means of a belt 86 to the shaft of the pay off reel 22 so that the shaft 84 runs in a normal clockwise direction. The shaft 84 runs in a clutch 88 which slips as long as the shaft 84 is running in a clockwise direction. This maintains the link 88 in the position shown in FIG. 9. However, if there is a break in the wire 20, then the wire 20 no longer pulls the pay off reel 22 in a clockwise direction and as a consequence, the motor 40 starts to run in a counter-clockwise direction. The pay off reel 22 starts to run in a counter-clockwise direction and so does the shaft 84. But once the shaft 84 starts to run in a counterclockwise direction, it engages the clutch 88, thereby causing the link 88 and pin 89 carried thereon to rotate around in a counter-clockwise direction to hit the arm 90 and close the limit switch 92.

Closing the limitswitch 92 provides a signal that shuts off all drive power and brakes the entire respooler. This limit switch 92 has a first set of contacts that are wired in parallel with the projecting strand detector finger circuit of FIG. 12 to perform the same braking operation as is performed when the detector fingers 50 detect a projecting strand. With reference to FIG. 12, this simply means that the limit switch 92 is connected as a normally open limit switch across the terminals T so that when the switch 92 is closed the circuit is completed to ground. This turns on the 2N877 silicon control rectifier and thus energizes the relays R and R to turn off power to the motor 26 and to brake the pay off reel 22 and take up reel 24. A second set of contacts on the limit switch 92 are also actuated to turn off all power to the motor 20. Since there is no need to maintain tension when a complete break in the wire occurs or when the pay off reel 22 is empty, there is no need for the motor 40 to operate and the pay off reel 22 shaft is brought to a stop as soon as possible with the use of the friction brake on the shaft of the pay off reel 22.

The sizing die A sizing die assembly 70 (see FIGS. 1, and 11) is positioned close to the take up spool 24. The sizing die 94 is a split sizing die through the center of which the wire 20 runs. The central opening in this sizing die serves to make sure that the twisted stranded wire 20 is kept to a certain maximum over all diameter. This sizing die 94 serves to compress loose twisting and to keep brazed ends down to size. Its function is well known in this art. Because of the fact that in many instances the detector stand 46 and take up stand 35 have to be placed relatively close to one another, detected projecting strand will reach the sizing die 94 before the respooler can be brought to a stop. If this occurs there may be damage to the wire. The wire may birdcage or it may under some circumstances catch in the sizing die 94 in such a fashion as to cause the wire to break in two. It thus becomes necessary that the sizing die 94 be opened very rapidly in response to a sensed projecting strand. A quick snap opening of the sizing die 94 is achieved by means of a solenoid 96 operated lever arm 98, which lever arm 98 raises the actuator arm 100 of a knee action clamp 102 that when opened pulls back a pusher arm 104 so that the helical springs 106 under tension can pull open one half of the split sizing die 94. When the fault has been repaired and the respooling operation is to continue the wire 20 is placed within the sizing die 94 and the operator pulls the actuator arm down to the position shown in FIG. 10 thereby causing the pusher arm 104 to push the sizing die 94 closed. Once closed the knee action of this clamp holds the pusher arm 104 closed against internal pressures within the sizing die 94 that will occur when the wire 20 is somewhat oversized. The actuator arm 100 must be lifted up in order to open this knee action clamp 102. To be lifted up requires either operator actuation or actuation by the lever arm 98 which occurs when the solenoid 96 is energized. The solenoid 96 is energized by the closing of one of the relays R and R in the FIG. 12 circuit. For example, the closing of the contact K in FIG. 12 could be employed to energize the solenoid 96.

A limit switch (not shown) mounted integrally with the clamp 102 is actuated only when the die is closed. The respooler will not start unless this limit switch is actuated so that operation cannot inadvertently be initiated with an open sizing die.

What is claimed is:

1. In a twisted stranded conductive-metal wire respooler, means for detecting projecting strands which comprises essentially, in combination:

(A) an electrically conductive member having a longitudinally open straight channel therein,

(B) a non-conductive insert lining the wall of said channel of said conductive member to provide a longitudinally open straight insulated channel adapted to receive the wire and to insulate the wire from said conductive member,

(C) said insert having sufficiently small wall thickness so that projecting strands from said wire being pulled through said insulated channel will strike said conductive member prior to entering said insulated channel,

(D) said insert having a length greater than the length of said channel of said conductive member and having its leading edge protrude forwardly slightly beyond said conductive member,

(E) a guide pulley adapted to have the wire fed over it,

(P) mounting means attached to said respooler mounting said pulley and said conductive member for travel of said wire successively over said pulley and from said pulley while longitudinally straight through said insulated channel from its leading edge to its trailing edge with said insert spaced from said pulley by a distance so that broken strands will whip free after the wire has left said pulley and before the wire enters said insulated channel,

(G) power-actuated means on said respooler for pulling said wire for said successive travel over said pulley and while longitudinally straight through said insulated channel,

(H) a resilient member comprised in said mounting means which is connected to and supports said conductive member and which permits resilient pivoting of said conductive member away from said wire being pulled through said insulated channel responsive to said insulated channel being struck by an obstruction on said wire being pulled therethrough, and

(I) a voltage source and circuit means associated with said source for electrically connecting whatever wire is being pulled through said insulated channel to a first terminal of said voltage source and connecting said conductive member to a second terminal of said voltage source to provide a completed electric circuit when a strand projecting from said wire being pulled through said insulated channel contacts said conductive member.

2. Apparatus according to claim 1 wherein said insulated channel has a depth greater than its width.

1 1 3. In a twisted stranded conductive-metal wire respooler, means for detecting projecting strands which comprises essentially in combination:

(A) a first electrically conductive member having a longitudinally open straight channel therein facing in a first direction,

(B) a first non-conductive insert lining the wall of said channel of said first conductive member to provide a first longitudinally open straight insulated channel adapted to receive the wire and to insulate the wire from said first conductive member,

(C) said first insert having sufficiently small wall thickness so that projecting strands from said wire pulled through said first insulated channel will strike said first electrically conductive member prior to entering said first insulated channel,

(D) said first insert having a length greater than the length of said channel of said first conductive member and having its forward edge'protrude forwardly slightly beyond said first conductive member,

(E) a second electrically conductive member having a longitudinally open straight channel therein which is substantially aligned with said channel of said first conductive member and which faces in a second direction substantially 180 opposed to said first direction,

(F) a second non-conductive insert lining the wall of said channel of said second conductive member to provide a second longitudinally open straight insulated channel adapted to receive the wire andto insulate the wire from said second conductive member,

(G) said second insert having a length greater than the length of said channel of said second conductive member and having its forward edge protrude forwardly slightly beyond said second conductive member,

(H) a guide pulley adapted to have it, I

(I) mounting means attached to said respooler mounting said pulley and said first and second conductive members for travel of said wire successively over said pulley and from said pulley while longitudinally straight through said first insulated channel from its leading edge to its trailing edge and then through said second insulated channel from its leading edge to its trailing edge with said first insert spaced from said pulley by a distance so that broken strands will whip free after-the wire has left said pulley and before the wire enters said first insulated channel and the wire fed over nel spaced substantially from the trailing edge of said first insulated channel in the direction of travel of the wire,

(J) power-actuated means on the respooler for pulling said wire for said successive travel over said pulley and while longitudinally straight through said first and second insulated channels,

(K) a first resilient member comprised in said mounting means which is connected to and supports said first conductive member andwhich permits resilient pivoting of said first conductive member away from said wire being pulled through said first insulated channel responsive to said first insulated channel being struck by an obstruction on said wire being pulled therethrough,

(L) a second resilient member comprised in said mount means which is connected to and supports said second conductive member and which permits resilient pivoting of said second conductive member away from said wire being pulled through said second insulated channel responsive to said second insulated channel being struck by an obstruction on said wire being pulled therethrough, and

(M) a voltage source and circuit means associated with said source for electrically connecting whatever wire is being pulled through said first and second insulated channels to a first terminal of said voltage source and connecting said conductive members to a second terminal of said voltage source to provide a completed circuit when a strand projecting from said wire being pulled through said insulated channels contacts either of said first and second conductive members.

4. 'Apparatus according to claim 2 wherein each of said first and second insulated channels has a depth greater than its width.

References Cited UNITED STATES PATENTS 904,045 11/1908 Edwards 174-155 971,619 10/1910 Klugh 174-155 3,037,162 5/1962 Jones et a1. 20061.13 XR 2,977,781 4/1961 Smith 242157 3,031,868 5/1962 Hoefer 242157 3,266,692 8/1966 Whitten 242-157 HERMAN O. JONES, Primary Examiner US. 01/ X.R.

with the leading edge of said second insulated chan- 242-157 

